638355487 has 24 divisors (see below), whose sum is σ = 832003920. Its totient is φ = 483960960.

The previous prime is 638355481. The next prime is 638355493. The reversal of 638355487 is 784553836.

It is an interprime number because it is at equal distance from previous prime (638355481) and next prime (638355493).

It is not a de Polignac number, because 638355487 - 2¹⁹ = 637831199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a self number, because there is not a number n which added to its sum of digits gives 638355487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638355481) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3939 + ... + 35947.

It is an arithmetic number, because the mean of its divisors is an integer number (34666830).

Almost surely, 2^638355487 is an apocalyptic number.

638355487 is a deficient number, since it is larger than the sum of its proper divisors (193648433).

638355487 is a wasteful number, since it uses less digits than its factorization.

638355487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32071 (or 32064 counting only the distinct ones).

The product of its digits is 2419200, while the sum is 49.

The square root of 638355487 is about 25265.6978332284. The cubic root of 638355487 is about 861.0351187561.

The spelling of 638355487 in words is "six hundred thirty-eight million, three hundred fifty-five thousand, four hundred eighty-seven".